This drink is one of the oldest in Mexico, dating back millenia. Initially a bitter concoction, it's evolved and become sweet and spiced.
In a blender or food processor combine chocolate, sugar, and the 1/2 to 1 teaspoon cinnamon. Cover and blend or process until finely ground.
In a large saucepan combine ground chocolate mixture and milk. Cook and stir over low heat about 10 minutes or until chocolate melts. Remove saucepan from heat; stir in vanilla and almond extract.
Beat with a rotary beater or Mexican molinillo (wooden beater) until very frothy. Serve in mugs. If desired, top with whipped cream. If desired, sprinkle with additional ground cinnamon.